1. Field of the Invention
This application relates to underwater measuring systems and methods. More particularly, it concerns near-field distance and position measuring systems and methods for use on submarine vessels engaged in undersea exploration, charting and like activities.
2. Description of the Prior Art
Many scientific and other type operations involving submarine vehicles require measurement of distance between two or more points or objects on a lake or ocean floor. Such operations can also require determination and recording of the relative positions of points or objects on a lake or ocean floor. For example, the location of core samples around a central sampling site is important to tracer studies and the determination of spatial heterogenosity. Also, underwater biological studies often require similar measurements to quantity spatial distributions of habitat and permit analysis of density and dispersion with nearest neighbor statistics. Hence, a need exists for non-intrusive systems and methods that can quickly make underwater, near range distance and position determinations with a reasonable degree of accuracy.
For the sake of brevity in disclosing and claiming the new systems and methods of the invention, in all the text that follows, the terms object or objects should be understood to include the terms point or points where the context would so indicate.
The typical manner of making measurements of the type discussed above has involved the combined use of a bearing compass and an optical range finder. The accuracy of such an approach when used in submarine vessels is poor to unacceptable. Thus, with underwater measurement systems and methods available heretofore, points separated by distances ranging from 2 to 10 meters can not be accurately measured. Many projects requiring accurate measurement of points within this range have depended upon rough estimations by the persons operating within the submersible.
Historically, telescopes have been used in combination with other items, e.g., gyros, theodolites, etc., to operate in a non-intrusive manner to determine azimuth position, alignment or like data relative to a remote object (see U.S. Pat. No. 3,936,947). More recently, collimated light beams from lasers have been used in similar manner to telescopes for like purposes in making angular, height, location or like determinations of remote objects (see U.S. Pat. Nos. 4,160,285; 4,227,776; 4,459,758 and 4,703,563). The present invention utilizes laser beams in new non-intrusive systems and methods that can quickly make distance and position measurements of submarine objects with an acceptable degree of accuracy.